STEEL BAR CONNECTOR FOR THREADED STEEL BARS

Abstract

 A steel bar connector for threaded steel bars according to the present invention is configured to include: a support for receiving a portion of each of a pair of threaded steel bars therein and being screw-coupled with the projecting threads of the threaded steel bars to support same; and a pair of retainers having a portion thereof inserted and screw-coupled into the support from both sides of the support, and having the interior thereof screw-coupled to the projecting threads to retain a pair of threaded steel rods, wherein the support and the retainers are characterized by simultaneously imparting tensile force and compressive force to each of the pairs of threaded steel rods.

Description

TECHNICAL FIELD

[0001] The present invention relates to a steel bar connector, specifically, a steel bar connector for threaded steel bars made to improve the binding force by embracing a pair of threaded steel bars therein while tentatively assembled to provide both compressive force and tensile force at the same time to the threaded steel bar when completely assembled.

[0002] The present invention relates to a steel bar connector for threaded steel bars made so that a pair of steel bars can be connected without having the bars rotated.

[0003] The present invention relates to a steel bar connector for threaded steel bars made to improve the durability by preventing shaking or unwinding caused by tension and compression from the outside when steel bar connection is completed.

[0004] The present invention relates to a steel bar connector for threaded steel bars made so that it is easy to check whether there is incorrect assembly by looking through the inside after steel bars have been completely connected.

BACKGROUND ART

[0005] The type of steel bar that is commonly used as a frame in the construction of reinforced concrete structures is deformed bars, on which there are protruding nodes horizontally and two parallel ribs vertically throughout the entire length of the bars in order to improve the bond stress distribution with concrete. Since steel bars are produced only in certain lengths for convenience in transportation and construction work, they often need to be connected. There are many different methods as to connecting deformed bars.

[0006] The most widely used method is lap splicing, in which the ends of two steel bars overlapped and wired together. In this method, the connection solely depends on the adhesion of the steel bars, so its safety is uncertain. Gas pressure welding, in which the ends of two steel bars are heated with oxy-acetylene gas flame and then connected together using a welding machine, often results in thermal deformation in the connected portion. This causes secondary stress, making the connected portion weaker than the steel bar base material. Threaded joint, in which the ends of two bars are up-set or the ribs and nodes are processed in circular shape through forging and then connected with a coupler for internal threads after processing the external threads through cutting and thread rolling method, external force is applied on the bars, causing other types of deformations in the connected portion than those that occur on the base material, thus making the bar weaker than the base material.

[0007] With regard to the rules and regulations related to the production of steel bars, it is required that the steel bars be produced while maintaining similar material properties with similar thermal expansion ratio as concrete in order not to make reinforced concrete structures break easily due to heat. In Korea, lap splicing is not permitted for the connection of steel bars that are thicker than D29 (diameter of 29 millimeters) according to the regulations related to connecting steel bars. Thus, as explained above, steel bars are connected through gas pressure welding or mechanical methods, which are connection methods that change the original material properties of steel bars with secondary processing that applies heat or external force on the steel bars. Such methods are inevitably permitted, as many different types of steel bar connectors have been developed to be used in connecting steel bars without changing the original material properties of the steel bars.

[0008] Further, due to the necessity of the most effective connecting method, threaded steel bars (1, 1a) consisting of threaded nodes (11) in the form of thread crests on the outside of the steel bars, as shown in Fig. 1, have been developed. Steel bars are connected using a sleeve (4z) with internal threads (41) to which the threaded nodes (11) of threaded steel bars (1, 1a) are bound together.

[0009] However, since the threaded nodes (11) of threaded steel bars (1, 1a) have long pitches and the shape of threads are not precise, the thread roots of the internal threads (41) on the sleeve (4z) are made larger than the threaded nodes (11) of threaded steel bars (1, 1a) to make screwing easier. So when two steel bars (1, 1a) are screwed together using a sleeve (4z), there is much clearance between the sleeve (4z) and the steel bars (1, 1a), which makes them unwind easily and slip.

[0010] In order to resolve this issue, clearance is removed by screwing lock nuts (5z) on the ends of the sleeve (4z) and grouting fillers are placed inside the sleeve (4z), but it is a tedious task to prepare grouting fillers separately and to put them in. In addition, the strength of the grouting fillers is only 10% of the steel bars, making it an unsafe binding. The pitches of the steel bars (1, 1a) are also long and the flank angles are wide. This makes the screwing of the lock nuts (5z) hard and causes a safety issue in which the lock nuts (5z) can easily loosen due to external vibration.

[0011] The two lock nuts (5z) are not assembled tentatively with the sleeve (4z) but are prepared as a separate part, making the management of the parts difficult. The lock nuts (5z) are also relatively small in size. This increases the risk of safety accidents due to falling of the nuts while connecting. Considering the characteristics of construction sites, where safety and constructability in work and cost-saving through speedy work is needed, the necessity of a steel bar connector that can be tentatively assembled is deeply felt.

[0012] In resolving this issue, Korean Registered Utility Model No. 0409526 discloses a technique in which, as seen in Fig. 2, a semi-circular sleeve (2) that is placed to embrace the threaded node (11) is prepared, and a lock nut (5) is screwed in on the left side of the semi-circular sleeve (2) to apply pressure to the slanted ends on the either side of the semi-circular sleeve (2) so that a threaded steel bar (1a) can be connected.

[0013] However, the existing techniques described above also consist of many different parts and thus makes storage and management difficult. So the issue of low constructability still remains.

SUMMARY OF INVENTION

TECHNICAL PROBLEM

[0014] The object of this invention is to resolve the issues explained above and offer a steel bar connector for threaded steel bars made to improve the binding force by embracing a pair of threaded steel bars therein while tentatively assembled, in order to provide both compressive force and tensile force at the same time to threaded steel bars when completely assembled.

[0015] The object of this invention is to offer a steel bar connector for threaded steel bars made so that a pair of steel bars can be connected without having steel bars rotated.

[0016] The object of this invention is to offer a steel bar connector for threaded steel bars made to improve the durability by preventing shaking or unwinding caused by tension and compression from the outside when steel bar connection is completed.

[0017] The object of this invention is to offer a steel bar connector for threaded steel bars made so that it is easy to check whether there is incorrect assembly by looking through the inside with the naked eye after steel bars have been connected.

SOLUTION TO PROBLEM

[0018] The steel bar connector for threaded steel bars according to the present invention shall be characterized by having a support that embraces a portion of each of a pair of threaded steel bars on the inside and supports the steel bars by being screw-coupled with the protruding threads of the steel bars, and a pair of retainers that is partially inserted into the support and screw-coupled on either side of the support and then retains a pair of the threaded steel bars by being screw-coupled with the protruding threads on the inside, and the support and the retainers providing tensile force and compressive force at the same time to each of the pair of the threaded steel bars.

[0019] The pair of retainers shall be characterized by having the same shape.

[0020] The either side of the support shall be characterized by having slanted parts in which the external threads that are screw-coupled with the retainer is formed at an angle, and the inside of the support shall be characterized by having steel bar-connecting threads with a pitch that corresponds to the protruding threads.

[0021] On one of the sides of the inside of the retainers shall be characterized by having internal threads with a pitch that corresponds to the external threads and protrusion-receiving threads with a pitch that corresponds to the protruding threads, and the external threads and the internal threads shall be characterized by having a pitch that is different from those of the protrusion-receiving threads and the steel bar-connecting threads.

[0022] The external threads and the internal threads shall be characterized by having buttress threads.

[0023] One of the sides of the support shall be characterized by having an inspection hole to make it possible to see from the outside the location of the end of a pair of the threaded steel bars inserted inside the support.

ADVANTAGEOUS EFFECTS OF INVENTION

[0024] The steel bar connector for threaded steel bars according to the present invention is designed to embrace the ends of a pair of threaded steel bars by being rotated while tentatively assembled and to provide both compressive force and tensile force to threaded steel bar at the same time when the threaded steel bars are completely assembled together.

[0025] In this invention, a pair of steel bars can be connected without having the steel bars rotated, which improves the usability and enhances the binding force.

[0026] This invention improves the durability of the steel bars by preventing shaking or unwinding caused by tension and compression from the outside when the connection of a pair of steel bars is completed.

[0027] Further, this invention has an advantage of being able to check whether there is incorrect assembly by looking through the inside after steel bars have been connected.

BRIEF DESCRIPTION OF DRAWINGS

[0028] 

Fig. 1 is an exploded perspective view showing the composition of a steel bar connector according to existing art.

Fig. 2 is a state diagram of use showing the composition of the steel bar connector according to an existing art (Korean Registered Utility Model No. 049526).

Fig. 3 is a state diagram of use of the steel bar connector for threaded steel bars according to the present invention.

Fig. 4 is an exploded perspective view showing the specific composition of the steel bar connector for threaded steel bars according to the present invention.

Fig. 5 is a longitudinal sectional view showing the specific composition of the steel bar connector for threaded steel bars according to the present invention.

Fig. 6 is an exploded longitudinal sectional view showing the specific composition of the steel bar connector for threaded steel bars according to the present invention.

Fig. 7 is a longitudinal sectional view showing steel bars before connection with regard to the steel bar connector for threaded steel bars according to the present invention.

Fig. 8 is a longitudinal sectional view showing a steel bar inserted inside the steel bar connector for threaded steel bars according to the present invention.

Fig. 9 is a longitudinal sectional view showing the rest of the steel bars before connection with regard to the steel bar connector for threaded steel bars according to the present invention.

Fig. 10 is a longitudinal sectional view showing a pair of steel bars tentatively assembled using the steel bar connector for threaded steel bars according to the present invention.

Fig. 11 is a longitudinal sectional view showing the connected state of the pair of steel bars with the outside of the steel bars when connection is completed using the steel bar connector for threaded steel bars according to the present invention.

DESCRIPTION OF EMBODIMENTS

[0029] Hereinbelow, the composition of the steel bar connector for threaded steel bars (hereinafter referred to as "steel bar connector (100)") of the present invention will be described in detail using the attached Fig. 3.

[0030] Fig. 3 shows the state diagram of use of the steel bar connector for threaded steel bars (100) according to the present invention.

[0031] The terms and expressions used in the specification and claims shall not be interpreted in the general ways as used in dictionaries. They shall rather be interpreted with regard to the concepts and meanings fit for the technical idea of the present invention, with the inventor abiding by the principle that he can appropriately define the terms and expressions in order to best explain his own invention.

[0032] Therefore, the embodiments and drawings disclosed in the specification are only the preferred embodiments of the present invention and do not represent the entirety of the technical idea of the present invention. So it shall be understood that at the time of its application, there may be various equivalents and modifications that could be used as its replacements.

[0033] As shown in the drawings, the steel bar connector (100) of the present invention aims to connect a pair of threaded steel bars (F) in one straight line and is composed of three components. It embraces the ends of a pair of threaded steel bars (F) on the inside by being rotated into one unit while tentatively assembled together.

[0034] Then, the either ends of the tentatively assembled steel bar connector (100) are rotated to provide compression and tension to the protruding threads (F') outside the threaded steel bar (F), and the final connection is completed.

[0035] More specifically, the steel bar connector (100) embraces each of the portion of the pair of threaded steel bars (F) on the inside, with the support (120) providing support by being screw-coupled with the protruding threads (F') of the threaded steel bar (F), is then screw-coupled as it is partially inserted inside the support (120) from either ends of the support (120), and includes on the inside a pair of retainers (140) that retains a pair of threaded steel bars (F) by being screw-coupled with the protruding threads (F'). When the support (120) exerts compressive force vertically on the threaded steel bar (F), the retainers (140) provide vertical tensile force to the threaded steel bar (F).

[0036] The pair of retainers (140) is made in the same shape so as to make management of parts easy, and is connected to the inside of the support (120) through a vertical hole on the inside.

[0037] Further, an inspection hole (122) is made in the middle of the support (120) so that the inside can be seen from the outside.

[0038] Therefore, the location of the pair of threaded steel bars (F) embraced inside the support (120) can be seen with the naked eye.

[0039] The composition of the support (120) and the retainers (140) will be explained in detail using the attached Fig. 4 to Fig. 6.

[0040] Fig. 4 shows an exploded perspective view of the specific composition of the steel bar connector for threaded steel bars (100) according to the present invention, Fig. 5 shows a longitudinal sectional view of the inside of the steel bar connector for threaded steel bars (100) according to the present invention, and Fig. 6 shows an exploded longitudinal sectional view of the inside of the steel bar connector for threaded steel bars (100) according to the present invention.

[0041] As shown in the drawings, there is a hole in the middle of the support (120) and the external diameter on either side gradually decreases as it reaches toward the ends.

[0042] Also, the inside of the support (120) has steel bar-connecting threads (126) that have the pitch and size that correspond to the protruding threads (F'). The steel bar-connecting threads (126) can be screw-coupled with the protruding threads (F') of the threaded steel bar (F) while embracing therein the ends of the pair of threaded steel bars (F) that they are close to or in touch with.

[0043] There is a pair of inspection holes (122) in the middle of the support (120) so that the inside of the support (120) can be seen.

[0044] There are slantedparts (124) on either ends of the support (120) where the external diameter gradually decreases. The slanted parts (124) have external threads (125) so that the retainers (140) and the support (120) can be screw-coupled together. Here, buttress threads are used as shown in the enlarged view in Fig. 5.

[0045] Thus, while the support (120) and the retainers (140) are put together, when force in opposite directions is applied, there is sufficient binding strength despite the slope in the slanted parts (124).

[0046] The retainers (140) include a pair of them in the same shape, bound together by being screw-coupled with the threaded steel bar (F) and the support (120) at the same time so that a pair of threaded steel bars (F) does not move.

[0047] More specifically, the retainers (140) are in a cylindrical shape with a vertical hole on the inside, and there are protrusion-receiving threads (144) on the inside.

[0048] The protrusion-receiving threads (144) are made to have the pitch and size that correspond to the threaded steel bar (F) and protruding threads (F') to be screw-coupled with the protruding threads (F'), and have the same pitch and size as the steel bar-connecting threads (126).

[0049] Also, the protrusion-receiving threads (144) extend only up to a certain percentage of the length of the retainers (140) and there are internal threads (142) for the rest of the length.

[0050] The internal threads (142) are made to be screw-coupled with the external threads (125) on the slanted parts (124) and are made slanted to correspond to the slanted parts (124).

[0051] In other words, the retainers (140) have an internal diameter that gradually decreases to a certain depth in the internal direction from one end, which is where internal threads (142) are.

[0052] The internal threads (142) are made with buttress threads as with the external threads (125) and are made to have the pitch and size that correspond to the external threads (125).

[0053] Thus, the retainers (140) can be bound together with the support (120) through the screw-coupling of the internal threads (142) and the external threads (125) and can be bound together with the threaded steel bar (F) through the screw-coupling of the protrusion-receiving threads (144) and the protruding threads (F').

[0054] Hereinbelow, the process of connecting a pair of steel bars using steel bar connector (100) will be explained in detail by using the attached Fig. 7 to Fig. 11.

[0055] Fig. 7 is a longitudinal sectional view showing a steel bar before it is connected using the steel bar connector for threaded steel bars (100) according to the present invention. The support (120) and a pair of retainers (140) are prepared as tentatively bound together as shown in in Fig. 7, and a pair of threaded steel bars (F) to be connected is also prepared.

[0056] Then, the steel bar connector (100) is located on the outside of a threaded steel bar (F) as shown in Fig. 8.

[0057] In other words, the steel bar connector (100) is rotated to be screw-coupled with the protruding threads (F'). Here, the protruding threads (F') are screw-coupled with the protrusion-receiving threads (144) of the retainers (140), the steel bar-connecting threads (126) of the support (120), and the protrusion-receiving threads (144) of the retainers (140), in this very order, to become what is shown in Fig. 8.

[0058] Fig. 8 is a longitudinal sectional view showing a steel bar inserted inside the steel bar connector for threaded steel bars (100) according to the present invention.

[0059] As shown in Fig. 9, a pair of threaded steel bars (F) are placed on the same straight line, and the steel bar connector (100) is rotated to move in the direction of the arrow.

[0060] Fig. 9 is a longitudinal sectional view showing the rest of the steel bar before it is connected with the steel bar connector for threaded steel bars (100) according to the present invention.

[0061] When the foregoing process is completed, the ends of a pair of threaded steel bars (F) are located on the inside of the steel bar connector (100) as shown in Fig. 10. The location of the ends of the threaded steel bars (F) can be seen from the outside with the naked eye through the inspection hole (122).

[0062] However, the steel bar connector (100) can cause slight movement on the pair of steel bars in the state as shown in Fig. 10.

[0063] In other words, Fig. 10 is a longitudinal sectional view showing a pair of steel bars tentatively assembled together using the steel bar connector for threaded steel bars (100) according to the present invention. Even when a pair of steel bars is inserted inside the steel bar connector (100), as shown in the enlarged view in Fig. 10, the protrusion-receiving threads (144) and the steel bar-connecting threads (126) do not exert pressure on the protruding threads (F'), so it could cause clearance on the threaded steel bar (F).

[0064] Therefore, the protrusion-receiving threads (144) and the steel bar-connecting threads (126) can be made to exert pressure on the protruding threads (F') by rotating and tightening a pair of retainers (140) in different directions as shown by the arrows in Fig. 10.

[0065] Fig. 11 is a longitudinal sectional view showing a pair of steel bars after the completion of connection using the steel bar connector for threaded steel bars according to the present invention, showing the contact with the outside of the steel bars. In a state shown in Fig. 10, as a pair of retainers (140) rotate in opposite directions and moves in the direction that makes them farther away from the support (120), a pair of threaded steel bars (F) receives tensile force from the retainers (140) due to the interference of the protruding threads (F') and the protrusion-receiving threads (144) as shown in the enlarged view below.

[0066] At the same time, the protruding threads (F') of a pair of threaded steel bars (F) located inside the support (120) receive compressive force from the support (120) due to the interference of the steel bar-connecting threads (126) as shown in the enlarged view above.

[0067] These actions occur because the protruding threads (F') touch the protrusion-receiving threads (144) and the steel bar-connecting threads (126) at the same time, while the support (120) and the retainers (140) are screw-coupled, and the size of the protrusion-receiving threads (144) and the steel bar-connecting threads (126) are larger than that of the protruding threads (F').

[0068] The scope of the present invention is not limited to the foregoing examples of the embodiment, and many different modifications would be available based on the present invention to those of ordinary skill in the art within the above-described technical field.

[0069] For example, in the embodiment of the present invention, the internal threads (142) and external threads (125) are made to be on slanted surfaces on the support (120) and the retainers (140), and they have corresponding pitch and size so that they could also be made around the inside or the outside with difference in height as long as they can be screw-coupled.

[0070] Further, in the embodiment of the present invention, the method of completing the assembly of the support (120) and the retainers (140) in directions in which they become farther away from each other was explained in Fig. 11, but they can also be connected more strongly with the tensile force and compressive force created on the outside of each of the threaded steel bars (F) even when the support (120) and the retainers (140) are rotated in directions in which they become closer together.

INDUSTRIAL APPLICABILITY

[0071] The steel bar connector for threaded steel bars according to the present invention embraces therein a pair of threaded steel bars while tentatively assembled and provides both compressive force and tensile force at the same time to the threaded steel bar when completely assembled.

[0072] Connection is possible without having the steel bar rotated.

[0073] Thus, the task of steel bar connection becomes simple and part management is easy, which makes it applicable in the wide scope of industrial sites.

[0074] When steel bar connection is completed, shaking and unwinding is limited, enhancing safety and reliability of structures.

[0075] Furthermore, after steel bar connection is completed, the inside can be seen from the outside with the naked eye to check whether there has been an incorrect assembly. So anyone can perform precise, strong connection of steel bars regardless of their level of skills, so its effectiveness is expected to be significant.

Claims

1. A steel bar connector for threaded steel bars, comprising: a support for receiving a portion of each of a pair of threaded steel bars therein and supporting the pair of threaded steel bars by being screw-coupled with the protruding threads of the threaded steel bar; and a pair of retainers having a portion thereof inserted and screw-coupled into the support from both sides of the support and the inside screw-coupled with the protruding threads,
wherein the support and retainers provide tensile force and compressive force at the same time to each of the pair of threaded steel bars.

2. The steel bar connector for threaded steel bars according to Claim 1, wherein the pair of retainers has the same shape.

3. The steel bar connector for threaded steel bars according to Claim 2, wherein there are slanted parts on both sides of the support with external threads on a slant that is screw-coupled with the retainers, and there are steel-bar connecting threads having a pitch corresponding to the projecting threads inside the support.

4. The steel bar connector for threaded steel bars according to Claims 3, wherein there are internal threads having a pitch that corresponds to external threads and protrusion-receiving threads with a pitch that corresponds to the protruding threads on the inside of the retainers, and the external threads and internal threads having a different pitch from those of protrusion-receiving threads and steel bar-connecting threads.

5. The steel bar connector for threaded steel bars according to Claims 4, wherein buttress threads are used for the external threads and internal threads.

6. The steel bar connector for threaded steel bars according to Claims 5, wherein an inspection hole is located on one side of the support to see from the outside the location of the end of a pair of threaded steel bars inserted inside the support.

Drawing